Giant Kidney Worm (Dioctophyme renale) in Dogs

Mammals that eat raw fish are most likely to contract dioctophyme renale because fish act as a host for one on the three stages of Dioctophyme renale. Dioctophyme renale is blood red in color. Adult females are sufficiently larger than their male counterparts.

Dioctophyme renale is indeed a giant (over a yard long) worm that can live in the kidney of a dog, cat, fox, human, pig or any predator but most commonly it is found in the mink. The worm is relatively rare. Although it is parasitic in nature, most mammals can live well with a giant kidney worm for years due to the other kidney compensating almost entirely. In spite of the alarming though of having such a worm in your dog (or your) abdomen, dioctophyme does not pose a significant risk.

A Dioctophyme renale infection is most commonly found after death. The carnivore host often has no symptoms at all because often times one kidney can serve the entire body. Not typical, but some dogs can experience renal pain, fever, inflammation of the abdominal wall or lumbar discomfort.

• Back pain
• Inflammation
• Abdominal pain
• Fever
• Weight loss

Types

The giant kidney worm passes through several stages before it can survive in the kidney of a carnivore for years. Eggs from a giant kidney worm happily residing in a carnivore are passed through urine and develop in freshwater for one to seven months. There they are swallowed by a freshwater worm. Then the worm is eaten by a fish or frog. If the fish or frog is eaten by a carnivore then Dioctophyme can reach sexual maturity. The giant kidney worm has different names for each stage of its parasitic life.

• Definitive - Mink, fox, dog, cat, human, pig
• Intermediate - Earthworm, freshwater worm
• Paratenic - Fish and frogs

Many of the larvae never reach their intended host and perish.

Your dog can contract giant kidney worm from eating raw fish or frogs. The giant kidney worm is considered rare but is typically found in temperate regions. It occurs across Europe, North and South America, Australia and Africa. An animal who drinks freshwater infested with freshwater worms that are serving as an intermediate host has the potential to contract juvenile Dioctophyme renale as well. Dioctophyme renale needs fresh water to embryonate. Cooking of fish and boiling of drinking water makes it easy to avoid.

Because the other kidney can and seemingly will, compensate for the kidney affected with Dioctophyme renale, diagnosis is often difficult. At times the dog will exhibit renal pain or kidney trouble. On occasion, eggs are found in the urine. Imaging tools (such as ultrasound) may show enlargement of the kidneys. An exploratory laparotomy (done by incision into the abdomen) may show the presence of the worm. In some cases the giant kidney worm is found during other abdominal procedures, such as a routine spay, and removed at that time.

The only known treatment of Dioctophyme renale is the surgical removal of the worm from the abdominal cavity. Sometimes the kidney has been devastated by the worm and it also needs to be removed. Dioctophyme renale almost always resides in the right kidney. This is found to be true across species. If surgery is needed, your pet will be put under general anesthesia and carefully monitored for the procedure.

Dioctophyme Renale is most commonly found in the right kidney. The left kidney will often compensate entirely causing the host little to no trouble. If the giant kidney worm is discovered and removed prognosis is excellent.

To ensure that your dog is not afflicted you may restrict him from eating raw fish or frogs. Dioctophyme is so rare that precautionary measures are often not taken. Although potentially devastating to the kidney, the ability to live comfortably with only one kidney also leads to lack of concern for this large parasite.